Soybean genome mapping could lead to improved varieties

A NEW TOOL

Achievement is highlighted in Nature magazine

While it probably won’t get the attention that the human genome, cow genome or even the cat genome got, the identification of the more than 46,000 genes in the soybean genome could be a big deal in a world hungry for more and better food, a cleaner environment and better products.

As announced in the January issue of Nature magazine, a team of scientists including members of the National Center for Soybean Biotechnology at MU’s College of Agriculture, Food and Natural Resources, announced that they have identified the location of approximately
1.1 billion base pairs in the soybean. In comparison, the human genome has approximately 3 billion base pairs.

Soybeans are one of the most important crop plants for their protein and oil, representing an almost $30 billion industry in the United States. The plant is a significant foodstuff in most of the world and the leading U.S. animal feed. It also is used in the manufacture of plastics, hydraulic oil and cleaning products.

Improved versions of these legumes, based on precise genetic information, could create more food that can be grown in more areas, as well as expand the soybean’s already impressive list of uses. Improved soybean oil used in deep frying could make French fries less of a risk for increasing cholesterol in people and positively impact the epidemic of obesity.

A better understanding of soybean characteristics couldn’t have come at a better time as soybeans are entering a new area of bio-diesel as a cleaner-burning alternative to petroleum. Given the soybean’s known ability to capture and sequester carbon in the atmosphere and turning it into protein and oil, the soybean may become an important method of achieving environmental balance.

Henry Nguyen, director of the center, says the genome sequence will be a new tool for plant breeders, industrial engineers, geneticists, biochemists and technologists, nutritionalists and others who use soybeans. The genome team has identified more than 90 distinct traits that affect plant development, productive characteristics, disease resistance, seed quality and nutritional traits.

“Perhaps the most exciting thing that we have found for the soybean community is the gene that confirms resistance to the devastating Asian soybean rust disease,” Nguyen says. “In countries where this rust is well established, soybean losses can range from
10 percent to 80 percent. Improved soybean strains resistant to the disease will greatly benefit production and increase foodstuffs around the world.”

With knowledge of what gene controls what soybean trait, scientists may be able to better adapt the plant to drought conditions, bringing a new cash crop and food product to poor areas of the Earth.
Gary Stacey, associate director of the MU center, initiated the project in 2007 through discussions with the Joint Genome Institute in California that is funded by the Department of Energy.

“The completion of this large, demanding project was only possible through the concerted efforts of the entire soybean community,” Stacey says. “Important contributions were made through state and national soybean checkoff organizations, such as the Missouri Soybean Merchandising Council and United Soybean Board, who funded some of the initial work. This foundation and the involvement of scientists at other universities, such as Stanford, Purdue and Iowa State, convinced the Department of Energy to fund the project.”

The human genome project, largely completed in 2003, is helping scientists to understand how genes express themselves, leading to diseases and genetic mutations. Nguyen has already begun collaborating with animal science and nutrition experts to modify soybeans added to animal feeds that could increase the health value of meat. Specifically, he is looking at ways to impart isoflavones, known to decrease the frequency of cancer, and proteins from soybeans into the meat.
People have been using soybeans for a long time. The annual plant has been used in China for 5,000 years to add nitrogen into the soil as part of crop rotation. Soybean meal has been a primary, low-cost protein for animal feeds for centuries. Soy vegetable oil has been consumed by people for a similar period. More recently, soybean derivatives have become a key component in industrial applications, particularly in paint, plastics, inks, solvents, cleaners and hydraulic fluid.
In 2009, approximately 74.7 million acres of soybeans were harvested in the United States yielding $29.6 billion in revenues for farmers. The economic impact of soybeans is second only to corn around the nation. Missouri is fifth in the country for soybean production, accounting for about $2 billion in sales. U.S. soybean exports were estimated at 1.1 billion bushels in 2009.
A particular area of growth for the bean is in energy. Soy biodiesel is cleaner burning than petroleum-based diesel oil. Its use reduces particulate emissions, and it’s non-toxic, renewable and environmentally friendly.

Production of U.S. biodiesel from soybeans is expected to increase from approximately 413 million gallons in 2009 to 648 million gallons in 2019, according to the 2009 World Agricultural Outlook by the Food and Agricultural Policy Research Institute (FAPRI).

Though a staple in the diets of many Asian countries, soybeans are not common on American tables except as oil. Ninety-eight percent of the U.S soybean crop is used for livestock feed and some dog foods. The nutritional benefits of the product are being slowly recognized. Soy-based infant formula is used for children allergic to cow milk proteins. Soy is rich in omega-3 fatty acids and isoflavones, and is credited with the ability to reduce serum cholesterol in humans.